This invention relates to a leaf spring valve that opens/closes or adjusts the flow path thereof and fulfills the function of a flow regulating valve and utilizes a spring as its valve body. More specifically, this invention relates to a leaf spring valve having a built-in drive valve body that has the force of stored energy and fulfills the function of a flow regulating valve, and utilizing this force of stored energy for driving and controlling the valve body, and to an air conditioning device using the leaf spring valve.
As typical valves for opening/closing the flow path, generally, there have been known ball valves which open/close the flow path by rotating a ball valve body disposed inside the valve main body thereof and provided therein with a through-hole and gate valves which open/close the flow path by vertically reciprocating a wedge-shaped valve body inside the valve main body thereof.
There is an electric motor-operated valve as one example of the automatic valve. This electric motor-operated valve has a construction which opens/closes or adjusts the flow path of a rotary valve such as a ball valve with an electric motor. A spring return type of electric motor-operated valve which generates an opening motion by means of a motor and a closing motion by utilizing the rewinding force of a spiral spring which has been rolled up as synchronized with the opening motion of the motor has been already reduced to practice.
As another special type of valve construction, a relief valve having a construction such that the opening of a cylindrical valve is opened/closed by means of a helical valve body formed of a shape memory alloy has been proposed (as disclosed in JP-A-HEI 10-30,420).
The flow regulating valve is of a type that controls the flow volume at a fixed level. Generally, it has mounted in the valve main body thereof a steady flow cartridge so selected as to conform to the set flow volume.
The various types of valve construction heretofore proposed and reduced to practice, however, entail the following problems.
For a start, the ball valve, i.e. a general type of valve, has such a construction that the ball valve body is rotated as pressed with a suitable compressible force against an annular ball seat and slid thereon. Thus, the force for rotation generally tends to be large and the size of the valve parts also tends to be large so as to retain strength. Since the valve body and the ball seat produce a closing/opening motion while accompanying a sliding motion, the ball seat tends to sustain wear. Since the ball seat possibly hurls itself out into the flow path by dint of the pressure of the fluid when the valve body assumes the position of intermediate aperture, the ball seat has the problem of dubious durability because it requires maintenance and replacement with a new seat in the course of a prescribed duration of use.
Then, the spring return type of electric motor-operated ball valve produces an opening/closing slide motion by means of a ball valve body and, moreover, requires a spring for charging the force to be used in imparting a return motion to the valve separately from the valve body. Thus, it suffers an undue increase in the torque of rotational operation (refer to the signs C, D, and E shown in the graph of FIG. 22) and consequently in the size of a finished product to the extent of inducing a rise in the cost.
The relief valve disclosed in JP-A-HEI 10-30,420 mentioned above is a valve formed of a shape memory alloy and, therefore, endowed with a construction capable of producing an opening/closing motion solely when a fluid having an elevated temperature exceeding a prescribed level is being supplied. Moreover, the shape memory alloy is a material of low yield and high price that not only adds to the cost of the valve but also betrays deficiency in the infallibility of opening/closing operation and in the practical value.
Then, the general flow regulating valve can cope only with the predetermined flow volume and, when the predetermined flow volume is changed, necessitates a troublesome work of replacing the built-in steady flow cartridge with a cartridge conforming to the new flow volume.
This invention has been initiated in view of the problems encountered by the various conventional types of valve. One object of the present invention is to provide a valve which, by a valve body acquiring a force of stored energy, is enabled to generate an opening/closing motion with a small torque of operation, render the generation of an opening/closing motion infallible and stable, further realize a reduction in cost, materialize manufacture of the valve in compact design, excel in durability and enjoy a high practical value. A further object of the present invention is to provide a valve that enables a valve body with a water stop function to diversify functionality by acquiring the function of fixing the flow volume and deriving a varying function of setting a steady flow volume from the rotational frequency of the valve shaft.
This invention relates, in the type of valve intended to open/close a flow path of a fluid, to a leaf spring valve which has accommodated in a valve main body a valve body formed of a bent leaf spring, with one end of the leaf spring fastened or fixed to the valve main body side and the other end thereof fastened or fixed to a valve shaft, and a bent surface thereof disposed opposite an inlet and an outlet of the flow path each terminating into a bent end face so as to be movable into and away from the inlet and outlet of the flow path, whereby the leaf spring is displaced toward the center of a valve chamber till the inlet and outlet of the flow path are opened by rotation of the valve shaft.
In this case, the leaf spring is a spiral spring and the outer periphery of this spiral spring is opposed to the inlet and outlet of the flow path.
The leaf spring valve contemplated by this invention is provided in a valve box with a drive valve body for opening/closing or controlling the flow path. This drive valve body has a force of stored energy that is utilized in controlling its drive.
In this case, the force of stored energy of the drive valve body is accumulated in the drive valve body by the output of an actuator that is an external drive force. This force of stored energy roughly equals the valve body force of drive control.
The drive valve body is also a spiral spring. This spiral spring has one end thereof fitted inside a valve chamber of the valve box, the other end thereof fitted to a valve shaft inside the valve chamber, and the lateral face thereof disposed as opposed to and depressed against a valve seat of the valve box. By rotating the valve shaft by means of an actuator or manually, thereby displacing the spiral spring centripetally toward the valve shaft side, it is made possible to separate the lateral face of the spiral spring from the valve seat and open the outlet of the flow path on the secondary side or shift the position for fitting the spiral spring inside the valve chamber to the proximity of the inlet of the flow path on the primary side.
Further, a seal member formed of an elastic material such as rubber is integrally formed with the spiral spring at the position for sealing the valve seat.
By suitably displacing the spiral spring centripetally toward the valve shaft side by means of the valve shaft that has been rotated with an actuator or manually, the spiral spring is enabled to possess the function of facing a steady flow volume. In this case, the rotational frequency of the valve shaft is relied on to set the steady flow volume at an arbitrary level.
The leaf spring valve described above is used particularly advantageously in an air conditioning device adapted to open/close or control a pipe for supply of a fluid or to acquire the function of fixing the steady flow volume.